In a feat that not many would attempt, Andrew Ainge is swimming to France.
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This is no pedestrian test, with the crossing of the English Channel demanding immense physical strength and mental stamina.
But for the father from Menston, there is a determination and will driven by personal circumstance.
His mother Ann, diagnosed with a terminal brain tumour, is still fighting. His ex-wife, diagnosed just a fortnight later, died in January.
And he is determined, for the first time in his life, to make a change.
"I've never done anything for charity," says the 49-year-old, who is raising funds for The Brain Tumour Charity. "But with this, it has become personal.
"Selfishly, all my life I've just done my own thing. Maybe I'm just getting old, and soft.
"That money, going into research, might one day find a cure."
Mr Ainge, a company director and father to seven-year-old Jay, is a keen athlete. What started with triathlons turned to an Ironman, then open water swimming.
Ice swimming became the international championships, and a medal, and now the Channel.
This is the 'Everest' for swimmers, says the open water coach at Leeds Bradford triathlon club. Planning began two years ago. But then his family life took a dramatic turn.
Brain tumour diagnosis
"We thought my mother had a stroke, and we took her to the doctors and then to hospital for a scan," said Mr Ainge.
"It turned out it wasn't a stroke, but a brain tumour, quite an aggressive one. Within seven days she was in hospital, having a craniotomy and the tumour removed."
With his mother's matter-of-fact attitude, said Mr Ainge, he has seen a new side to her. Given the option to operate or die within two weeks, she had told the surgeon to crack on.
"She's inspired me," he said. "I've never seen that strength in her before - I've just seen her as my mother.
"At the same time, my ex-wife Sally, worked at the same hospital. She didn't know, but she also had the same tumour. It was terminal, grade four.
"Two weeks after my mum had the operation, Sally started having these symptoms. Sadly, she passed away in January."
Mrs Ainge, at 70, is still fighting. A second scan revealed a second growth, but it has since shrunk.
"As she puts it, she'll be here for another Christmas," said Mr Ainge. "She's sorted everything.
"As soon as she thought she was going to have 18 months, she planned the funeral, what music she was going to be having, what cars were going to be there.
"She's done everybody's birthday and Christmas cards for the next 20 years. In her opinion, she's 70, she's had a good life and when the time comes, it comes.
"But for Sally, she left the world at age 43. She had remarried, she had two kids. It is incredibly sad."
Mr Ainge is in his 'window' for the challenge today, hoping to swim tonight. He left for Dover on Thursday.
There is a food schedule, mapped plans. A crew, aboard the Viking Princess, piloted by the same captain who escorted David Walliams on his own successful attempt.
Fewer than 1,800 people have ever completed this. The Channel crossing, although only 21 miles wide, will see Mr Ainge swimming around 35 miles because of the tides.
It will take 49,000 arm rotations, and burn up to 20,000 calories. Unable to stomach food as he swims, Mr Ainge will only be allowed liquids, one short burst every hour on the hour.
Warm carb drinks, black tea with fruit sugars. And the water will be around 14C.
"In simple terms, I'm swimming from Dover across the English Channel to France," he says.
"There's the cold, the jellyfish, the night swimming. Everybody told me it wasn't realistic, that people train for this for 20 years. Now I'm on my way.
"There's a friend that I train with, and we always say 'what would Rocky do?' It's not how much you can take, it's how much you can take and keep moving forward.
"I like that concept. I have to put it into little blocks. Never look back, and never look forward. Just keep knocking those chips down."
Andrew Ainge is raising funds for The Brain Tumour Charity, to donate click here or visit the charity at www.thebraintumourcharity.org
He is due to swim tonight, but this is weather dependent. For live updates and to follow his progress, click here.